Katharine,
If your development times are long try incrasing bleach concentration 2 times. This is visual development anyway. On the other hand it is hard to believe thta Loris is using 10x concentration of bleach and getting good results. Perhaps this is not that critical. I did not like very concenrated bleach because it continued bleeding/developing for a long time.
MM
> Date: Sat, 1 Dec 2007 09:27:17 -0800
> From: kthayer@pacifier.com
> Subject: Re: Bleach-development with gum
> To: alt-photo-process-l@usask.ca
>
> Loris, thanks for the report; I look forward to seeing your better
> results.
>
> I am inclined to think that my poor results may be related to the
> size/hardener, and possibly partly to the amount of dichromate. I
> agree with Marek that my first mix (that produced the most mottled
> print) made too thick a layer because it was so heavily pigmented,
> but that wasn't true of the less pigmented mix, that also eventually
> mottled after repeated exposure to the bleach. It's interesting to
> me that such a strong bleach you're using doesn't just take the image
> right off the paper.
>
> I actually really liked something I was getting yesterday, a very low-
> key print reminiscent of Bill Jacobson's dark portraits. I pulled it
> out too soon and it dried down too dark, but I may try that again to
> see if I can get a similar effect to how it looked when wet. In
> fact, I guess I could just put it back in the bleach and let it
> develop farther.
> kt
>
>
>
> On Dec 1, 2007, at 9:02 AM, Loris Medici wrote:
>
> > Katharine,
> >
> > I got much better results - but there's still plenty of room for
> > improvement methinks, will share them soon...
> >
> > But, the bleach I use is 55% sodium hypochlorite, not 5% as yours
> > (many sodium hypochlorite based bleach brands in Turkey are 55%).
> >
> > For bleach development, I use 2x the amount of pigment I would
> > normally use, I cut the dichromate to 1/2x (5%), and exposure is
> > around 3x (or 4x if I find the coating is on the thick side).
> >
> > I use 20ml of 55% bleach per liter of water. I first rinse the
> > print to get rid of the dichromate then put into bleach for 1
> > minute (face down), then I put into development water for 10
> > minutes, then I evaluate the print and put into bleach for another
> > minute - if it acts in a lazy manner - and continue to develop in
> > water.
> >
> > Actually I did a wonderful print yesterday but ruined it later
> > because I was a little bit impatient and pulled it early in
> > development (I should give it 5-10 minutes more) and when I left it
> > for drying (flat) I got serious stain (in form of bleeding).
> >
> > I get best results on unsized paper. I get flaking with sized paper
> > - I don't know why!? I never managed to make an acceptable print on
> > sized paper (both 3% and 6%, hardened with formalin) - kind of a
> > curse I guess...
> >
> > Anyway, even if the results are very good considering they're one-
> > coat gums, their Dmax is still less than what I get from properly
> > done 3-coats... Will try harder.
> >
> > Regards,
> > Loris.
> >
> > Quoting Katharine Thayer <kthayer@pacifier.com>:
> >
> >
> >> This isn't working very well for me; I don't know why. I've
> >> posted
> >> a couple examples from an afternoon's efforts.
> >>
> >> The main dilemma seems to be that if I leave the print in the bleach
> >> for longer periods of time (10-15 minutes) I get blotching and
> >> mottling of the image, (both with highly pigmented and normally
> >> pigmented mixes of lamp black) but if I soak it in the bleach for
> >> shorter periods of time (1-5 minutes) then development is too slow
> >> for
> >> my patience. Perhaps I've overexposed too much at 3x normal, but I
> >> wouldn't have thought so. The bleach I'm using is Western Family
> >> brand; ingredients are listed only as Sodium hypochlorite 6%, "Other
> >> ingredients" 94%. I've used it diluted at 15ml/liter of water. Gum
> >> coating mix is, as always, 1 unit gum/pigment: 1 unit saturated
> >> ammonium dichromate. Arches bright white paper, sized with
> >> gelatin/glyoxal. I've included a normal print, for comparison.
> >>
> >> http://www.pacifier.com/~kthayer/html/Bleachdev.html
> >>
> >>
> >>
> >> On Nov 27, 2007, at 1:52 PM, Marek Matusz wrote:
> >>
> >>
> >>> Very interesting thread. I was in the Big Bend NP hiking and
> >>> taking pictures, happy without a computer or cel phone for a few
> >>> days. I only got to read some of the emails now.
> >>> Here is my comment from the practical standpoint of a gum
> >>> printer. My one coat gum prints have eveloved to a practice that
> >>> gives maximum darks and long (relative) tonal range of the final
> >>> print (not to be confused with long negative density range).
> >>> Some of my prints were included in the travelling portfolio last
> >>> time around.
> >>> Here is a description of my pratice.
> >>> Coat the paper with gelatine / harden it.
> >>> FOr the gum layer I prefer highly pigmented carbon black.
> >>> Use longer exposure (3 to 5 times normal exposures). I really
> >>> have not tried to push it even further.
> >>> Soak in water to remove dichromate.
> >>> Develop in a weak chlorox solution. My dilution is about 20 cc/
> >>> liter of water. Could be as little as 10cc if I want slow action
> >>> or as much as 40 to 50. Once the print starts bleeding the
> >>> pigment I place it in water and watch for a few minutes
> >>> following the development. If the development is slow, dip back
> >>> in chlorox for a few minutes. The reason for moving it back and
> >>> forth is that the action of chlorox continues for a few minutes
> >>> and it is easy to just wash the gum layer completely.
> >>> Actually I use this method a lot for my tricolor gum prints as well.
> >>>
> >>> How close is that to direct carbon? I call it gum, but it has
> >>> all the ingredients mentioned in this discussion, geletine,
> >>> gum, chlorox (or Javelle water version)
> >>> Marek
> >>>
> >>>
> >>>> Date: Tue, 27 Nov 2007 07:58:31 -0700
> >>>> From: zphoto@montana.net
> >>>> Subject: Re: The Fresson/Arvel Process
> >>>> To: alt-photo-process-l@usask.ca
> >>>>
> >>>> Thank you, Dave!
> >>>>
> >>>> However, the only thing nice and generous about me is my butt
> >>>> after sitting
> >>>> on it all weekend, 24/7, taking notes out of the 300+ pages I
> >>>> took digipix
> >>>> of at Geo Eastman House. But it is DONE!!! One further milestone.
> >>>>
> >>>> Snippet from an 1896 book I told you I'd share about a possible
> >>>> Artigue
> >>>> formula; they were always trying to guess at it..Since Artigue
> >>>> died with
> >>>> his secrets and the Fresson family doesn't seem to be willing to
> >>>> share
> >>>> theirs, it is interesting to look at discoveries before the
> >>>> Artigue paper
> >>>> that might have been in the air. So this may be worthless but
> >>>> what the
> >>>> heck:
> >>>>
> >>>> "1863 Mr. Blair of Bridgend took plain paper, coated it with
> >>>> gelatine and
> >>>> dried; then next coated with albumen mixed with a little syrup,
> >>>> and dried.
> >>>> Then floated on water and blotted and carbon powdered pigment
> >>>> was brushed
> >>>> onto the surface in a thin film on top of the albumen.
> >>>> Sensitized by
> >>>> floating on a solution of pot bi. He did not use gum on top of
> >>>> the gelatin
> >>>> because it did not take kindly to it and it was more apt to run
> >>>> together
> >>>> under the operation of the brush and leave small blank spaces,
> >>>> and was also
> >>>> tackier under moisture, and took up too much pigment." (not a
> >>>> direct quote)
> >>>>
> >>>> I think that electron microscopy nowadays says that gum IS in
> >>>> Fresson paper
> >>>> along with gelatin (at least, that is what I read in Chakalis'
> >>>> patent) but
> >>>> the way this paper is described in the text is even,
> >>>> translucent, and
> >>>> velvety like the Artigue. It seems that when a lower solution of
> >>>> pot bi
> >>>> (like 2-5%), warm or hot water development, sawdust, eau de
> >>>> Javelle are
> >>>> used, gelatin is in the paper. I marvel at their exposing the
> >>>> direct carbon
> >>>> paper for HOURS in the SUNLIGHT before developing it in Javelle.
> >>>>
> >>>> BTW, any who may be confused about the differences between
> >>>> carbon printing
> >>>> and direct carbon (not you Sandy, John, Art) of which we are
> >>>>
> >>> talking, carbon
> >>>
> >>>> printing is the term nowadays used to refer to a transfer
> >>>> process where the
> >>>> tissue of exposed gelatin is transferred to another piece of paper,
> >>>>
> >>> but back
> >>>
> >>>> in "the day" the term "carbon printing" referred to the gum process
> >>>> originally. Then the term was swiped in a drive-by for the
> >>>> carbon transfer
> >>>> process so towards the end of the century the term "direct carbon"
> >>>>
> >>> came into
> >>>
> >>>> use for both gum printing and such things as Arvel, Artigue,
> >>>> etc. papers
> >>>> even if carbon pigment wasn't used. So when researching I always
> >>>> have to
> >>>> xerox articles that talk about pigment printing, carbon
> >>>> printing, direct
> >>>> carbon, bi-gum, gum-bichromate (that little hyphen becomes
> >>>> important in
> >>>> searches), etc. Direct carbon was not transferred to another
> >>>> piece of paper
> >>>> hence the operative word "direct".
> >>>> Chris
> >>>>
> >>>>
> >>>> ----- Original Message -----
> >>>> From: "Dave Soemarko" <fotodave@dsoemarko.us>
> >>>> To: <alt-photo-process-l@usask.ca>
> >>>> Sent: Tuesday, November 27, 2007 6:26 AM
> >>>> Subject: RE: The Fresson/Arvel Process
> >>>>
> >>>>
> >>>> > << There are no immediate plans on my agenda to make the
> >>>> process I use
> >>>> > available on the market. But like yourself I am willing to
> >>>> help others to
> >>>> > experiment with the Direct Carbon system by pointing them towards
> >>>>
> >>> relevant
> >>>
> >>>> > published information. >>
> >>>> >
> >>>> > John and Chris,
> >>>> >
> >>>> > Both of you are very nice!
> >>>> >
> >>>> >
> >>>> > Dave
> >>>> >
> >>>> >
> >>>>
> >>>>
> >>>>
> >>>
> >>>
> >>> Connect and share in new ways with Windows Live. Connect now!
> >>>
> >
> >
> >
> >
>
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